Heuristic Fallback in cuDNN: Why THD Format Reverts to SM80 on Hopper GPUs

[TGS123]

"Why does the forward pass call the cuDNN SM90 interface when the learnable_sink option is enabled with qkv_format="bshd", but reverts to the cuDNN SM80 interface when qkv_format="thd" is selected in sdpa?"